Tuesday, March 4, 2025

Space Travels to Other Worlds: Oxygen, Water & Food Problems (Part 4)

Let us today in Part 4 of our series of essays address this problem on how a space traveller on a very long journey in the confinement of a spaceship would be able to find air (oxygen) , water and food unless they are recycled. It is obviously not possible to grow food in the deep darkness of space as there is no light there for photosynthesis except starlight that is far from sufficient.

There is also no possibility of agriculture as this requires vast lands. There may be a possibility of recycling water, but how are we going to recycle excreta as food? This is revolting and psychologically unacceptable even if possible. Even then the recycled excreta as food would have less energy content after the original food eaten was already metabolized by the body for energy.

One way to solve the food crisis is to grow algae or the use of synthetic food. Again, this requires a lot of light and energy. Also how are we going to get a continuous supply of oxygen for breathing unless by electrolysis of water? But this will yield hydrogen as well. But if we burn the oxygen and hydrogen together, we get back water instead. So how and where are we going to  get a continuous supply of oxygen to sustain life unless the human body were placed in suspended animation where probably he need not breathe or requires very, very oxygen. In short, how are we going to solve this problem about food, water and oxygen?

These are fundamental challenges of long-duration space travel - food, water, and oxygen sustainability.  Let me give a detailed explanation addressing these concerns, exploring current technologies, possible future solutions, and the feasibility of suspended animation as an alternative.

 

Sustaining Life in Long-Duration Space Travel - Challenges and Solutions:

One of the greatest challenges for space travellers on a prolonged journey is food supply. Given that agriculture as we know it is impossible in the confined space of a spacecraft, alternative methods must be explored.

 

Recycling Organic Waste:

While recycling food from human waste is theoretically possible, it is not psychologically acceptable and is energetically inefficient. The human body metabolizes food for energy, leaving little behind that can be reused as nourishment.

 

Algae Cultivation:

Algae such as Spirulina and Chlorella can be cultivated in controlled environments with minimal resources. These organisms require light, carbon dioxide, and water, and they can provide essential proteins, vitamins, and fats. Artificial LED lighting could be used in place of sunlight to facilitate photosynthesis, though it would require an energy source.

 

Synthetic Food Production:

Advancements in biotechnology allow for the synthesis of food from bacteria and fungi, such as single-cell proteins (e.g., mycoproteins). These require minimal resources and can be grown in bioreactors. Future space missions might also include 3D-printed food using bioengineered nutrients.

 

Water Supply and water recycling:

Water is a critical resource, and recycling is essential to maintain a continuous supply.

NASA’s Environmental Control and Life Support System (ECLSS) on the International Space Station already recycles urine, sweat, and wastewater through a filtration and purification system. This technology will be crucial for extended space travel.

 

Extraction of Water from Asteroids:

Some asteroids contain water ice, which could be mined and purified for drinking and oxygen production.

 

Oxygen Supply:

A continuous supply of oxygen is essential for human survival in space. Several methods have been proposed:

 

Electrolysis of Water:

Splitting water molecules (H₂O) into hydrogen and oxygen through electrolysis is a viable way to produce breathable oxygen. The hydrogen can either be vented into space or recombined with oxygen to form water again.

 

Algae and Plant Oxygen Production:

Photosynthetic organisms, such as algae and plants, naturally absorb carbon dioxide and release oxygen. Closed-loop bioregenerative life support systems (BLSS) could utilize this natural cycle.

 

Oxygen Harvesting from Lunar or Martian Regolith:

Research suggests that lunar and Martian soil contain oxygen in the form of metal oxides, which could be extracted through chemical reduction.

 

Suspended Animation as an Alternative:

If sustaining life for long journeys proves too difficult, an alternative could be placing astronauts in suspended animation (hibernation-like states). This would drastically reduce oxygen, food, and water requirements. Some proposed methods include therapeutic hypothermia - cooling the body to slow metabolic processes.

Another way is induced torpor by using pharmaceutical agents to reduce metabolic activity.

Conclusion

Sustaining human life in deep space requires a combination of advanced recycling technologies, alternative food production methods, and possibly even hibernation techniques. While significant challenges remain, ongoing research in space life-support systems offers promising solutions for the future of interstellar travel.

 

 

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